1 files changed, 3 insertions, 1 deletions
diff --git a/ruby/tests/basic.rb b/ruby/tests/basic.rb
index ad34d53d..d151022e 100644
--- a/ruby/tests/basic.rb
+++ b/ruby/tests/basic.rb
@@ -336,7 +336,9 @@ module BasicTest
 
       # strings are immutable so we can't do this, but serialize should catch it.
       m.optional_string = "asdf".encode!('UTF-8')
-      assert_raise RuntimeError do
+      # Ruby 2.5 changed to raise FrozenError. However, assert_raise don't
+      # accept subclass. Don't specify type here.
+      assert_raise do
         m.optional_string.encode!('ASCII-8BIT')
       end
     end